# OS_InitIrqTable

## C Specification

  `#include <nitro/os.h>`
  `void OS_InitIrqTable( void );`

## Description

This function initializes the IRQ interrupt table.

This IRQ interrupt table is for registering, by individual IRQ interrupt cause, the functions that jump when an IRQ interrupt occurs. Functions that do nothing are set for the IRQ interrupt, but `DMA` and `TIMER` interrupts register the interrupt handler provided by OS. This interrupt is only called by the OS handler when a user has registered the handler, but nothing is registered at first. A user does not need to distinguish this difference. So it looks to a user that nothing is done with all the interrupts after `OS_InitIrqTable` is called (that a function that does nothing is called.).

## Arguments

None.

## Return Value

None.

## See Also

`OS_SetIrqFunction`, `OS_GetIrqFunction`

## Revision History

03/01/2004 Updated description for operation when initialization
12/01/2003 Initial Version